Severe Thunderstorm Warning 207, NWS Des Moines, IA

000 
WWUS53 KDMX 171101
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
601 AM CDT TUE JUL 17 2007

IAC017-171115-
/O.CON.KDMX.SV.W.0207.000000T0000Z-070717T1115Z/
BREMER IA-
601 AM CDT TUE JUL 17 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 AM CDT
FOR BREMER COUNTY...

AT 600 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED 11 MILES SOUTH OF READLYN...OR ABOUT 10 MILES EAST OF
WATERLOO...MOVING SOUTHEAST AT 45 MPH.


LAT...LON 4264 9254 4288 9257 4289 9256 4291 9256
      4293 9254 4292 9217 4266 9212
TIME...MOT...LOC 1101Z 333DEG 63KT 4253 9215

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
318 AM CDT TUE JUL 17 2007

.SHORT TERM /TODAY/...
OUTFLOW BOUNDARIES SCATTERED ACRS THE CWA EARLY THIS MORNING
FROM CONVECTION THAT OCCURRED LAST EVENING.  HOWEVER...MAIN
THERMAL/MOISTURE GRADIENT REMAINS FARTHER NORTH INTO MINNESOTA.
ELEVATED CONVECTION MOVING SOUTH QUICKLY IN SOUTHERN MINNESOTA TO
NORTHEAST IA WHERE 850-700MB THERMAL ADVECTION IS STRONGEST. EXPECT
THIS CONVECTION TO RIDE ALONG IN THE MEAN FLOW THROUGH THE MORNING
WITH MAIN IMPACT IN OUR FAR NORTHEAST CWA.  CERTAINLY SOME SEVERE
WEATHER MAY OCCUR WITH THESE STORMS...MAINLY FROM LARGE HAIL BUT
SOME STRONG WIND GUSTS MAY ALSO OCCUR. WL ALSO CONTINUE TO MONITOR
THE HYDROLOGIC SITUATION AS PWATS REMAIN AOA 1.50 INCHES ACRS MUCH
OF THE CWA.  OTHERWISE...THERMAL RIDGING WL NUDGE INTO THE STATE AS
CONVECTION MOVES TO THE EAST.  EXPECT MOST OF THE CWA TO CLIMB INTO
THE 90S BY AFTERNOON ALTHOUGH THE NORTHEAST PORTIONS WL BE
CONDITIONAL ON THE AMOUNT OF SUNSHINE RECEIVED.  THIS WL ALSO
PRODUCE STRONG INSTABILITY BY AFTERNOON WITH SBCAPES IN EXCESS OF
2500 J/KG.  THOUGHTS ARE THAT CONVECTION THIS AFTERNOON WL BE
LIMITED TO THE FAR NORTHEAST CLOSEST TO THE SFC BOUNDARY.
HOWEVER...ANY OUTFLOW PRODUCED BY THE MORNING CONVECTION MAY ALSO
ACT TO PUSH UP SOME STORMS.  NEEDLESS TO SAY...HIGHEST AFTERNOON
POPS WL BE IN THE NORTHEAST.  ANY STORMS THAT DO DEVELOP COULD
BECOME SEVERE FAIRLY QUICKLY WITH LARGE HAIL AND DAMAGING WINDS THE
MAIN THREAT.  HEAVY RAINFALL WL ALSO REMAIN LIKELY AS PWATS HOLD
FROM 1.5 TO 2 INCHES.

.LONG TERM.../TONIGHT-MONDAY/...
ACTIVE WX WL CONTINUE THROUGH THURSDAY AS SHORTWAVES DIVE THROUGH
THE REGION IN BROAD NORTHWEST FLOW.  NEARBY BOUNDARY WL PROVIDE
FOCUS FOR THUNDERSTORM DEVELOPMENT PRIMARILY IN NORTHERN IOWA FROM
TONIGHT INTO WEDNESDAY AND THEN INTO CENTRAL AND SOUTHERN PORTIONS
OF THE STATE BY LATER WEDNESDAY INTO THURSDAY.  INSTABILITY ALONG
AND SOUTH OF THE BOUNDARY WL REMAIN STRONG DURING THIS PERIOD AS
AMPLE MOISTURE WILL BE IN PLACE.  THIS WL ALLOW CONVECTION TO BE
SEVERE AT TIMES WITH LARGE HAIL AND DAMAGING WINDS BOTH POSSIBLE.
IN ADDITION...PWATS WL REMAIN FROM 1.5 TO 2 INCHES WITH HIGH
RAINFALL RATES LIKELY WITH THE STORMS.  WOULD NOT BE SURPRISED WITH
SOME LOCALIZED FLASH FLOODING DURING THIS TIMEFRAME AS STORMS PASS
OVER THE SAME AREAS FROM TIME TO TIME.  WITH PASSAGE OF SIGNIFICANT
WAVE ON THURSDAY...FRONT WILL BE PUSHED SOUTH OF IOWA WITH HIGH
PRESSURE BUILDING INTO THE UPR MIDWEST.  SUBSIDENCE AND DRIER AIR WL
END PCPN THREAT BY FRIDAY ACRS THE STATE.  TEMPERATURES WL ALSO
MODERATE AS A CANADIAN AIRMASS FILTERS INTO THE STATE.
THEREAFTER...LARGE UPPER RIDGE BEGINS TO BUILD ACRS THE WESTERN INTO
CNTRL PORTIONS OF THE UNITED STATES.  THIS WL SHIFT THE JET WELL
NORTH INTO CANADA WITH WARM AIR ENVELOPING MUCH OF THE LOWER 48.
THE THREAT FOR PCPN WL ALSO REMAIN LOW WITH LITTLE FORCING ACRS THE
STATE.

&&

.AVIATION...17/06Z
WILL LIKELY KEEP NEAR TERM MENTION OF THUNDER OUT OF ALL TAFS GIVEN
THE UNCERTAINTY ABOUT IF/WHERE ANY ADDITIONAL CONVECTION WILL
DEVELOP OVERNIGHT. THERE MAY BE SOME REDEVELOPMENT AGAIN DURING THE
AFTERNOON BUT CONFIDENCE STILL TOO LOW TO MENTION.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

AVIATION/SHORT TERM...KINNEY/FORSTER
LONG TERM...COGIL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
526 AM CDT TUE JUL 17 2007

IAZ004>007-015>017-024>028-036>039-048>050-061-062-075-086-097-
181100-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-HAMILTON-HARDIN-GRUNDY-
BLACK HAWK-STORY-MARSHALL-TAMA-JASPER-POWESHIEK-MAHASKA-WAPELLO-
DAVIS-
526 AM CDT TUE JUL 17 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
IOWA...MAINLY EAST OF A LINE FROM EMMETSBURG TO AMES AND OTTUMWA.

.DAY ONE...TODAY AND TONIGHT

EXPECT PERIODS OF THUNDERSTORMS TODAY INTO TONIGHT WITH THE BEST
COVERAGE EAST OF INTERSTATE 35 AND NORTH OF HIGHWAY 30. SOME
STORMS MAY BE SEVERE WITH LARGE HAIL AND DAMAGING STRAIGHT LINE
WINDS. AN ISOLATED TORNADO IS POSSIBLE DURING THE LATE AFTERNOON
AS WELL. HEAVY RAIN WILL ALSO BE LIKELY WITH ANY STORMS WITH
LOCALIZED FLASH FLOODING A POSSIBILITY.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SCATTERED THUNDERSTORMS ARE FORECAST ON WEDNESDAY INTO THURSDAY AS
WELL. SEVERE STORMS REMAIN POSSIBLE WITH LARGE HAIL AND DAMAGING
WINDS. HEAVY RAINS WILL ALSO REMAIN POSSIBLE.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL LIKELY BE NECESSARY AT VARIOUS TIME TODAY
AND TONIGHT. SPOTTER ACTIVATION MAY ALSO BE NEEDED ON WEDNESDAY
INTO THURSDAY.

IAZ023-033>035-044>047-057>060-070>074-081>085-092>096-181100-
POCAHONTAS-SAC-CALHOUN-WEBSTER-CRAWFORD-CARROLL-GREENE-BOONE-
AUDUBON-GUTHRIE-DALLAS-POLK-CASS-ADAIR-MADISON-WARREN-MARION-
ADAMS-UNION-CLARKE-LUCAS-MONROE-TAYLOR-RINGGOLD-DECATUR-WAYNE-
APPANOOSE-
526 AM CDT TUE JUL 17 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
IOWA...MAINLY WEST OF A LINE FROM POCAHONTAS TO DES MOINES AND
CENTERVILLE.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS TODAY AND TONIGHT.
SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. TEMEPRATURES WILL
ALSO BE QUITE WARM BY THIS AFTERNOON WITH HIGHS IN THE LOW TO MID
90S WITH HEAT INDICIES OF 100 TO 105 DEGREES.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE THREAT FOR THUNDERSTORMS WILL INCREASE BY LATER WEDNESDAY AND
CONTINUE INTO THURSDAY. SOME SEVERE STORMS WILL BE POSSIBLE WITH
LARGE HAIL AND DAMAGING WINDS THE MAIN THREAT. HEAVY RAINFALL IS
ALSO EXPECTED WITH THESE STORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED TODAY OR TONIGHT.
HOWEVER...SPOTTER ACTIVATION MAY BE NECESSARY BY LATER WEDNESDAY
INTO THURSDAY.

CC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
428 AM CDT TUE JUL 17 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0421 AM     TSTM WND GST     WATERLOO AIRPORT        42.56N 92.40W
07/17/2007  M61 MPH          BLACK HAWK         IA   ASOS

&&

COGIL